Artificial arm.



E. W. HOBBS.

ARTIFICIAL'AHM.

APPLICATION FILED MAR. 6. I9I8.

Patented Aug. 6, 1918.

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UNITED STATES PATENT OFM@ ARTIFICIAL ARM.

Specification of Letters Patent.

Patented Aug. 6, 1918..

Application filed March 6, 1918. Serial No. 220,790.

To all 'whom t may concern:

Be it known that I, EDWARD IVALTER HoBBs, a subject of the King of England, residing in Balham, Surrey, England, have invented certain new and useful Improvements in Articial Arms, of which the following is a specification.

This invention is for improvements in or relating to artificial arms and has for its object the provision of means which enable a wrist-bucket connected by side-irons to joints borne by the upper-arm sockets to receive a twisting movement about the axis of the fore-arm while the side-irons nevertheless maintain the connection of the bucket with the elbow-joint pivots.`

The invention is fully described with reference to the accompanying drawings in which- Figure 1 is a side elevation of an artificial arm suitable for a low amputation;

Fig. 2 is a plan of the same, and

Fig. 3 is a detail end view of Fig. 2. Y

Like reference letters indicate like parts throughout the drawings.

Referring to these drawings, there is illustrated a construction of artificial arm which is suitable for a patient who can twist the stump of bis wrist or forearm, so that no special mechanism is required for effecting the twisting of the wrist. In order to retain the usual forearm bucket B securely in position it is desirable that an upper arm soclet A of the usual type should also be use Two metal strips G, or a single strip suitably shaped, are securedl along the sides of the bucket B, and they carry a plate G1 which lies in a plane perpendicular to the longitudinal axis of the forearm. Two tierods H are each lprovided with universal joints which preferably comprise spherical ends H1, engaged in suitable sockets H2 H3 provided respectively on a side-iron of the upper-arm strap A, and on the strip G near the plate G1 as shown. These rods H are stiff and inextensible and provide a secure but flexible connection between the wristplate G1 and the upper-arm strap A. While the rods are preferably stiff, they may be flexible enough to bend slightly over the patients arm, when the wrist is twisted from the position shown in Fig. 1 through a considerable angle, say 90. Y

Conveniently there may be combined with the plate G1 fixed at the outer end of the wrist-bucket B a second plate G2 for carrying an artificial hand or other device. This second plate G2 is pivoted to the bucketplate G1 on a cross-axis transverse to the axis of the forearm. It is also provided with a locking device preferably comprising a rigid arcuate lug G3 concentric with the cross-axis and notched as at G4. On the bucket plate G1 is a manually controlled latching lever G5 (Fig. 3) to engage the notches G"1 of the arc G3 on the plate G2 for the urpose of locking that plate and the arti cial hand or attachment carried by it in any of the positions to which they may be together adjusted about the cross-axis aforesaid.

A light spring G6 holds the lever G5 up against the lug G3, or in engagement with a notch G4. The plate G1 is slotted at G7 to permit the entry of the lug G3 when the plate G2 is turned about the pivotal cross axis aforesaid.

What I claim as my invention and desire to secure by Letters Patent is 1. In an artificial limb the combination with a plate secured on or at the outer end of a wrist-bucket or the like of stiff or slightly flexible side-irons that extend along opposite sides of the limb and, for the purpose described, are universally jointed (for example by ball-joints) to the plate and to a mounting on the patients upper arm.

2. The combination with the subject-matter of preceding claiming-clause No. 1 of a second plate for carrying an artificial hand or equivalent device, said plate being pivoted to the bucket-plate on a crossaxis transverse to the axis of the forearm and also provided with locking means to secure it in any desired angular position about said axis (for example a rigid arc concentric with the cross-axis and notched, and a manually-controlled latching lever mounted on the bucket-plate for the purpose of engaging the notches in said arc).

In testimony whereof I aflix my signature.

EDWARD WALTER HOBBS.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

